Excess Rain Means Pesky Mosquitoes!

Due to the all of the April and May rainfall in Texas, we are now experiencing a higher population of another pest insect, the mosquito. Mosquitoes are a diverse group of flies that are found worldwide, with about 85 species living in Texas.
Mosquitoes develop through complete metamorphosis with an egg, larva, pupa and adult stage. Mosquito eggs may be laid individually or in clusters on the surface of water or in dry locations that will periodically flood. The eggs hatch into larvae that eat bacteria, fungi and other organic debris in the water. The larvae will develop into pupae, which do not feed. The adult stage will emerge from the water to take flight.
Adult male and female mosquitoes feed on nectar, honeydew and fruit juices. The female mosquito will consume blood in order to develop her eggs. This causes the female mosquitoes to be the most DANGEROUS ANIMAL in the world, since they are capable of transmitting such diseases as Malaria, West Nile Virus, Eastern Equine Encephalitis, and Yellow Fever worldwide.
Some Control Options Outdoors:
The number one way to reduce mosquito populations in your yard is source reduction! Mosquitoes need as little as a bottle cap full of water to complete their lifecycle, so all areas where water collects needs to be emptied or changed weekly. If standing water is eliminated in your backyard, then the overall mosquito population in your area will be reduced.
1) Areas containing water should be changed or emptied weekly, such as wading pools, buckets, bird baths, pet dishes, ponds, boat covers, irrigation systems, and French drains.
2) Holes or depressions in trees should be filled with sand or mortar.
3) Leaky pipes and faucets should be repaired.
4) For standing water that can not be drained, one suggestion is to use mosquito dunks containing Bacillus thuringiensis israelensis (Bti) to kill the mosquito larvae.
Mow tall grasses and reduce the amount of foliage to reduce the resting sites for adult mosquitoes. Insecticides can be applied to trees and shrubs, such as those containing permethrin, in order to kill adult mosquitoes.
Some Options To Prevent Mosquito Bites:
1) Avoid wearing dark colors, since mosquitoes use visual cues to locate hosts.
2) Avoid exercising or yard work in the heat of the day, since mosquitoes are attracted to carbon dioxide and perspiration.
3) Avoid wearing fruity or floral fragrances in perfumes, deodorants, hair products, or sunscreens, since these scents are more attractive to mosquitoes.
4) Wear long, loose-fitting clothing to avoid mosquito bites.
5) Chemicals can be applied to the skin to prevent bites. DEET, has been an effective repellent that can be applied to the skin to repel mosquitoes. There are also other mosquito repellents on the market such as picaridin, oil of lemon eucalyptus, oil of eucalyptus, and soybean oil-based repellents that can be applied to the skin.

Asian tiger mosquito, Aedes albopictus (Skuse) (Diptera: Culicidae). Photo by Dr. Bart Drees, Professor and Extension Entomologist, Texas A&M Univeristy.

Swarms of Bees

Swarms of bees occur most commonly during the early spring when new queens decide to form a new nesting site. These bee swarms are less likely to be aggressive so we usually do not have to worry about stinging. However, these swarms tend to cause uproars in urban areas, if the nest settles in a backyard tree or on a porch. Also if the bees find a way to invade structures and take up residence in walls or attics, it could lead to a pretty expensive removal. If nests are not removed, the wax, honey and dead bees may produce odors that can attract other pests such as mice, ants, or cockroaches.
Some people prefer to leave their wild bee swarms alone. However if you wish to take action, the safest course is to hire a beekeeper to remove the swarm or hire a professional to eliminate it before they discover a way into structures. For more information about bees, please visit http://honeybee.tamu.edu.

An Outbreak of Sawflies!

An outbreak of pine sawflies defoliating pine trees in Lamar, Kaufman and Hunt counties have been reported, mainly on the loblolly pine. Although its identity has not been confirmed, it is likely one of the Neodiprion species of pine sawflies. Different species of sawflies cause periodic, widespread defoliation of pines throughout the southern states. The leaves (needles) of infested pines may be chewed down to the fascicles at the base of the needle bunches.

Sawflies are the only suborder of wasps, in the order Hymenoptera, that are plant feeders. They are greenish in color with dark longitudinal stripes and orange to black heads.

According to the Texas Forest Service entomologists, Joe Pase and Dr. Don Grossman, most affected trees should recover and re-leaf with no treatment. According to Pase, “The larvae feed mostly on 2nd year needles and leave the current year’s growth intact. The result is that few trees die from the defoliation. When tree mortality occurs, it is usually from attacks by pine engraver beetles (pine bark beetles) responding to stressed trees. Even then, few trees are attacked by pine beetles. Because the new growth on the trees this year has not progressed very far, the trees look especially bad, but I think most of them will come through OK – they just need a little time for the new growth to develop.”

If you feel that chemical treatment is needed, then applications of carbaryl or a pyrethroid insecticide such as bifenthrin or permethrin are suggested. Note that B.t. and spinosad are not effective against sawflies, since they are not true caterpillars.

There is usually more than one generation a year, so watch for additional feeding in late May or June. Trees that have been previously attacked may experience re-infestation by the 2nd generation. However, diseases and natural enemies usually keep later sawfly generations under natural control.

Sources: Joe Pase III, Entomologist, Texas Forest Service, jpase@tfs.tamu.edu and
Mike Merchant, Texas AgriLife Extension Entomologist, http://insectsinthecity.blogspot.com/.


Photo by: Pam Corder, Kaufman County Urban Forester.

The May Beetles Are Here!

As the weather warms, we will begin to see the adult May beetles (Phyllophaga spp.) flying under lights at night. These adults feed on leaves of several trees including oaks and pecans and can cause complete defoliation of the tree if large numbers of adults appear. Most healthy trees recover quickly from complete defoliation, but stressed trees can be damaged by these attacks.
The female May beetle will deposit eggs into the turf and the eggs will hatch into “c-shaped” grub worms that are creamy white in color with brown heads. The grubs feed on dead organic matter and roots of plants. Since the grubs feed on roots, they can injure roots of grasses and other plants. This causes infested turf to brown and it can be easily removed in large clumps.

Some Control Options:

Irrigating the soil with ¼ to ½ inches of water prior to treatment can improve the effectiveness, since the grubs will move closer to the soil surface. Parasitic nematodes in the genera Steinernema and Heterorhabtitis have been shown to be effective. Insecticides containing imidacloprid, halofenozide, and clothianidin are some active ingredients that are effective at killing the smaller stages of grub worms and ideally should be applied 6 weeks after adults emerge. Lambda-cyhalothrin and trichlorfon are some examples of active ingredients more effective at killing the larger grub worm stages.

Picture of grub worms. Photo by Texas A&M University.

Time to treat for fire ants!

Red imported fire ants, Solenopsis invicta Buren, are an invasive species that has infested over 300 million acres in the southern United States. On average, Americans spend over $6 billion a year on medical bills, repairing damage to electrical wiring and purchasing insecticides for treatment of fire ants. For these reasons, the use of chemicals is needed to manage their populations, in order to allow the native ant species back into the landscape.
Fire ant baits, drenches, dusts and contact insecticides may be applied to control fire ants. It is advised to treat the individual fire ant mounds directly if less than 5 mounds are found within a 1/4 acre or less than 20 mounds within 1 acre, since this is not considered an infestation. However, if more than 5 mounds are present within a 1/4 acre or 20 mounds within an acre, then a fire ant bait or contact insecticide should be broadcasted over the entire infested area. Fire ant baits are made up of defatted corn grit covered with insecticide and soybean oil. The delivery process of baits into the colony is so effective, that the amount of insecticide applied within an area is significantly reduced. Before broadcasting the fire ant bait, foraging activity should be assessed, by placing a potato chip or hot dog next to the mound. If fire ants find the chip or hot dog within twenty minutes, then it is a suitable time to broadcast the bait. Fire ants will typically actively forage when the soil surface temperature is between 70 and 90° F, which is between May and September. Fire ant baits should never be watered into the soil and they should not be applied if they smell rancid. On the other hand, contact insecticides can also be broadcasted over the entire infested area and need to be watered into the soil. Control using contact insecticides generally lasts for 6 to 12 months, depending on the active ingredient within the insecticide.
Both fire ant baits and contact insecticides can be broadcasted using a hand-held spreader for small areas or a Herd Seeder can be mounted onto a truck or ATV for larger areas.
For more information, please visit the fire ant webpage at http://fireant.tamu.edu.


Photo of fire ant workers. Photo by Bart Drees, Professor and Extension Entomologist, Texas A&M University.

Mining the Leaf

Moving plants indoors during the winter allows for excellent breeding conditions for many insects. One of these flying insects a leafminer agromyzid fly in the genus Liriomyza. Liriomyza leafminers can be found on numerous outdoor plants, including chrysanthemums, asters, zinnias, marigolds, daisies, eggplant, carrot, potato, garden peas, lettuce, tomato, cucumber, and pepper plants.
Adult leafminers are 1/16 inches in length with grayish-black bodies and yellow markings. The female flies insert their eggs into the leaves. The eggs hatch usually in 2 days into 1/16 inch larvae. These whitish-yellow larvae cause plant damage, by tunneling through the leaf tissue. As the larvae mature, the tunnel or mine gets larger in size. After 7 or 8 days, the last larval stage emerges from the leaf to pupate in the soil. The adult fly will emerge usually in 7 to 11 days. The lifecycle from egg to adult may last all year, if the leafminer is in a controlled environment.
The white tunnel that appears on the leaf is both unappealing to the eye and can cause leaf drop in some instances. Leaf mines reduce the value of the crop and they can reduce the photosynthetic ability of the plant. If large populations exist, they have the potential to retard growth of young plants and lower fruit yield.

Some Control Options

Some Cultural Control Options:

1) Prune off and dispose of infested leaves and branches.
2) Properly irrigate and fertilize plants to ensure healthy plants.
3) Plant cultivars that are more tolerant to leafminer attack.
4) Cover the soil with plastic to prevent larvae from pupating.

Some Chemical Control Options:

Organics sprays such as horticultural oil, neem and spinosad can be used to control leafminers. Also systemic insecticides such as acephate and imidacloprid can be used to control leafminers.


Photo of leafminer adult, Liriomyza sp. Photo by: Texas AgriLife Extension, Department of Entomology, Texas A&M University.

Attack of the Aphids

Aphids are small, soft-bodied winged or wingless insects about 1/25 to 1/8 inches in length, with relatively long legs and antennae. Aphids can vary in color from black, green, yellow to even pink. Some aphids lay eggs, while others give birth to live young that can mature in as little as 7 to 8 days. Aphids have piercing-sucking mouthparts that remove phloem from the plant, causing distortions in young leaves and stunting new growth. They can also feed on flower buds, which cause deformities.
Since aphids feed on phloem they excrete honeydew, which is a shiny, sticky waste product that collects onto lower lying leaves. Once deposited, the honeydew is a nice food source for sooty mold which will begin to grow on the underlying foliage. Sooty mold will inhibit photosynthesis, so its growth can potentially cause severe harm to the plants.

Some Control Options

Some Non-Chemical Control Options: Conserve beneficial insects, such as spiders, praying mantids, assassin bugs, lacewings, ladybird beetle larvae and adults and parasitic wasps in outdoor landscapes. Also spraying water streams is effective to dislodge aphids from plants.
Some Chemical Control Options: Insecticidal soaps and oils can be used to control aphids and are considered low impact insecticides. Other foliar insecticides containing such active ingredients as permethrin, cyfluthrin, carbaryl, deltamethrin, pyrethrins and tebufenozide or systemic insecticides such as those containing imidacloprid or acephate can also be used.

Photo of crape myrtle aphids, Tinocallis kahawaluokalani (Kirkaldy) (Homoptera: Aphididae. Photo by Bart Drees, Professor and Extension Entomologist, Texas A&M University.